PROBLEM TO BE SOLVED: To accurately and easily measure a continuous blood pressure value and a blood pressure-related value in an upper arm or the like without invasion of a living body. SOLUTION: An optical sensor for detecting a pulse wave corresponding to a blood vessel diameter, a pulse wave corresponding to a thin blood vessel in a shallow part of a living body obtained from the optical sensor, and a thick blood vessel such as an upper arm or a shallow temporal region. With the differential value calculating means for calculating the differential value of one to a plurality of orders of the pulse wave corresponding to, the feature point detecting means for detecting the feature point for each pulse wave obtained by the differential value calculating means, and the feature point detecting means. It comprises a blood pressure-related value measuring means for measuring a blood pressure-related value based on the phase difference between the obtained feature points. Further, it is composed of an electrocardiogram signal detecting means for detecting an electrocardiogram signal and a blood pressure-related value measuring means for measuring a blood pressure-related value based on a phase difference by combining an optical sensor for detecting a pulse wave corresponding to a blood vessel diameter. .. [Selection diagram] Fig. 1【課題】 生体無侵襲で、連続した血圧値、血圧関連値を、上腕部等において、正確に且つ簡便な血圧の測定を行う。【解決手段】 血管径に対応した脈波を検出するための光学センサ、前記光学センサからえられた生体浅部の細い血管に対応する脈波と上腕部、または浅側頭部等の太い血管に対応する脈波の１乃至複数階数の微分値を算出する微分値算出手段、前記微分値算出手段で得られた脈波ごとの特徴点を検出する特徴点検出手段、前記特徴点検出手段で得られた特徴点間の位相差に基づいて血圧関連値を測定する血圧関連値測定手段よりなる。 更に心電図信号を検出するための心電図信号検出手段、血管径に対応した脈波を検出するための光学センサの組み合わせにより同様に位相差に基づいて血圧関連値を測定する血圧関連値測定手段よりなる。【選択図】図１
